Mexican Breast Cancer Research Output , 2003-2012

Breast cancer is the most commonly diagnosed malignancy and leading cause of cancer mortality among women in the world (de la Vara-Salazar et al., 2011; Haghighat et al., 2012; Ferlay et al., 2013). The mortality rate in developing countries is even higher because of limited medical infrastructure and awareness (El-Basmy et al., 2012; Kutikhin et al., 2012; Siegel et al., 2012; Pandey and Chandravati, 2013). Since 2006, breast cancer has been the leading cause of cancer mortality in Mexican women, accounting for 14% of cancer-related deaths (Chavarri-Guerra et al., 2012; Justo et al., 2013). The government of Mexico has developed diverse efforts and initiatives to confront the rise in mortality due to said cause, including early detection, treatment and research strategies (Gonzalez-Robledo et al., 2010). Research evaluation consists of monitoring of ongoing research initiatives to assess the efficiency and effectiveness with which they are being implemented, to determine the extent to which they are achieving their targeted objectives, and to recommend adjustments. On this premise, the present study was designed to determine the Mexican share of published research in the field of breast cancer from 2003 to 2012. A bibliometric method was used to analyze breast cancer research trends and performances including international collaboration, distribution of institutes and author publications.


Introduction
Breast cancer is the most commonly diagnosed malignancy and leading cause of cancer mortality among women in the world (de la Vara-Salazar et al., 2011;Haghighat et al., 2012;Ferlay et al., 2013).The mortality rate in developing countries is even higher because of limited medical infrastructure and awareness (El-Basmy et al., 2012;Kutikhin et al., 2012;Siegel et al., 2012;Pandey and Chandravati, 2013).Since 2006, breast cancer has been the leading cause of cancer mortality in Mexican women, accounting for 14% of cancer-related deaths (Chavarri-Guerra et al., 2012;Justo et al., 2013).The government of Mexico has developed diverse efforts and initiatives to confront the rise in mortality due to said cause, including early detection, treatment and research strategies (Gonzalez-Robledo et al., 2010).
Research evaluation consists of monitoring of ongoing research initiatives to assess the efficiency and effectiveness with which they are being implemented, to determine the extent to which they are achieving their targeted objectives, and to recommend adjustments.On this premise, the present study was designed to determine the Mexican share of published research in the field of breast cancer from 2003 to 2012.A bibliometric method was used to analyze breast cancer research trends and performances including international collaboration, distribution of institutes and author publications.

Materials and Methods
In this study, Web of Science, which covering nearly all fields of science, was used to produce statistics on the scientific production of the mexican researchers.Mexican papers (articles, research notes, and review articles) in the field of breast cancer were downloaded for the 10 publication years, 2003-2012.In order to approximate the overall number of published items on breast cancer, the following search strategy was employed; CU=mexico AND TS=[(phyllodes tumo$r$) OR (Cystosarcoma Phyllo$des) OR (Malignant Cystosarcoma Phyllodes) OR (breast invasive ductal carcinoma) OR (infiltrating duct carcinoma$) OR (mammary ductal carcinoma$) OR (breast cancer) OR (breast neoplasm$) OR (breast tumo$r$) OR (human mammary neoplasm$) OR (human mammary carcinoma$)]; where TS= Topic search, $=any character.
Document information included names of authors, titles, years of publication, source journals, contact addresses, and subject categories of journals.The records were downloaded using Microsoft Excel software, and additional coding was manually performed for the number of authors, origin countries and institutes of the collaborators.The papers were also classified by their research level (clinical observation or basic research) and main types of research (metabolics, diagnosis, epidemiology, genetics, pathology, prognosis, quality of life, radiotherapy, screening and surgery).

Results
A total of 256 Mexican items published in Web of Science from 2003 to 2012 including the search words "breast cancer", "mammary ductal carcinoma" and "breast tumour", was counted (Figure .1).A development trend was found for all documents and articles, which increased from 6 in 2003 to 50 publications in 2012.The 256 indexed items have been cited 2,206 times since 2003.Figure 1 demonstrates the parallel increase in the number of citations in conjunction with the increase in published items.
The collaboration with different countries was estimated by the location of the affiliation of at least one author of the published papers.Of all the 256 articles with author addresses, 185 (72.26%) were Mexico independent articles and 71 (27.73%) were internationally collaborative articles.Domination in collaborative country was the USA (63.38%) followed by France (7.04%), Spain (5.6%), and Germany (4.22%).Figure 2 demonstrates the parallel increase in the number of collaboration international total items in conjunction with the increase in collaboration USA items.
The contributions of Mexican different institutes were estimated by the affiliation of at least one author.The 256 items were published by 58 Mexican institutes that collaborated with 74 foreing institutes.Of the 256 articles with Mexico author addresses, 133 (51.91%) were independent articles and 123 (48.09%) were interinstitutionally collaborations of two or more institutes.The top 10 institutes were ranked by the number of items (Table I).The National Autonomous University of Mexico had the most total (22.26%),followed by National Institute of Cancerology (21.87%),The Social Security Mexican Institute (20.31%),National Institute of Public Health (12.11%), and Center for Research and Advanced Studies (9.37%).
The clinical observation studies were the dominant study type with 164 items (64%), while the basic research studies had 92 items (36%).Figure 3 demonstrates the parallel increase in the number of clinical observation ítems in conjunction with the increase in basic research items.The main types of research are shown in Figure 3, metabolics and pathology dominate with 45.7% of the total output between them.
Finally, we examine the sources of funding for Mexican cancer research.Of total items only 73 (28.5%) had one or more explicit funding sources.National Council of Science and Technology funded the most total articles with 54 items (73.97%), followed by National Autonomous University of Mexico with 12 items (16.44%),Science and Technology Institute of Federal District with 10 items (13.70%),The Social Security Mexican Institute with 7 (9.59%), and National Institute of Health of USA with 7   .2013.14.10.5921 Mexican Breast Cancer Research Output, 2003-2012 (9.59%).No industrial company was involved in authoring items.

Discussion
Breast cancer is an emerging public health problem globally, including Mexico.Breast cancer research evaluation allows answering questions related to the performance of research to determine the extent to which they are achieving their targeted objectives, and to recommend adjustments.
In this study dealing with breast lung cancer Web of Science journal papers, we obtained some significant points on Mexican breast cancer research trends and performances from 2003 to 2012.Our findings suggest a growing interest in breast cancer research in Mexico as shown by the increased number of ítems each year.With respect to scientific collaboration, the USA ranked first in internationally collaborative items with Mexico.The National Autonomous University of Mexico was the leader in breast cancer research in Mexico, distinctly followed by National Institute of Cancerology and the Social Security Mexican Institute.Finally, the distribution by research type is similar to that of the rest of the world.
Several papers have examined cancer research in individual countries: in Canada (Campbell et al., 2010), Japan (Ho et al., 2010), and Puerto Rico (Calo et al., 2010).Particularly, there is a study related to portuguese breast cancer research (Donato and De Oliveira, 2006).As these studies, the results of this present analysis are consistent with other studies that have demonstrated an increase in breast cancer research publications worldwide (Glynn et al., 2010;Healy et al., 2011).
This work represents the first bibliometric assessment of Mexican breast cancer research.Breast cancer research in Mexico is still developing, although some research has attained an international level.The findings of this study should provide useful information for those who will be performing research and studying breast cancer for Mexican.

Figure 1 .
Figure 1.A) Internationally Collaborative Countries of Mexican Breast Cancer Research.Collaboration international total (solid line) and collaboration USA (dashed line); B) Mexican Breast Cancer Research Outputs in the Web of Science.Items (solid line) and cites per paper (dashed line) and; C) Mexican Breast Cancer Research Outputs by Research Level.Clinical observation (solid line) and basic research items (dashed line)